Röntgen-ray apparatus.



S GABOT. R'O'NTGEN HAY APPARATUS.

APPLICATION FILED $EPT.23,1912.

Patented May 5, 191 i.

SEWALL CABOT, or rnoounmn. usssn cnosn'r'rs.

nbn'mnn-miz ArrAnArus.

Specimen letters Patent.

Patented May .3, 1914.

W Application filed September 28, 1812. Serial No. 721.946.

To all whom it may concern:

Be it known that l. Sswhm. CAnor, a citizen of the United States, and a resldent of Brookline. in the county of Norfolk and State of Massachusetts, have invented a new and useful Improvementv in Bfintgen-Ray Apparatus, of which the following is a specification.

My invention relates to the production of Rontgen rays.

The object of my invention is to cause the tube in a conditipn'of vacuum which will give rays of the owest penetrating. quality desired, to emit rays of any definite penetration quality desired dependent upon a definite adjustment of the apparatus for gen-. erating electrical energy and at the same time to be able to govern the quantity of rays produced to have any value desired up to the full capacity of the apparatus without any change in quality taking place caused by said change in quantity.

I have found that the penetration quality.

of Rontgen rays is substantially determined by the voltage maintained in the tube terminals and quantity substantial] I determined by the coulombs perfsecon' Tpassing through the tube. Q

So far as I am aware in practically all forms of apparatus to-dayused" for producing Rtlntgen rays, current in the-tube is governed by raising or loweri causes a which for reasons connected with technique in Riintgenol it is desirable to avoid.

- I have foun it possible to accomplish the object of my invention by using a charged condenser whose voltage is maintained at the desired value by the apparatus for generating unidirectional electrical energy and keeping this volta fixed at any desired value. I govern t e coulombs per second through the tube b varying the proportion of the total time t at the tube is connected to the condenser.

My invention may best be understood by having reference to the drawing. Fi re 1 shows a front elevation of a mechamcally-driven rotary switch, with certain details omitted for the sake of clearness, for

the. terminal controlling the connection of the tube to the source of high potential. Fig. 2 shows in diagram details omitted from Fig. 1.

In Fig. 1 the motor M is connected to thc shaft S by flexible coupling A., Rotatin members G C carried on shaft S consist 0 two disks of, insulating material in the pe riphery of which are nine equally spaced conductin segments twenty degrees in length (5 own in Fig. 2). These serve-to intermittently connect and disconnect'the circuit through pairs f brushes m m m m and m m m m (shown in Fig. 2). The shaft S revolves in journals B B on which are mounted disks D D. carryinf'bruslnholders it h and k h. or the aforesaid brushes. Disk D may be permanently secured to B.

nged to be rotatable on B by control handle H through angle of twenty degrees.

In Fig. 2 the. condenser K is shown permanently connected to any source of high unidirectional potential having terminals 7 The double pole double throw switch F throws the circuit through the rotary switches from. parallel to series when thrown from right to left and vice versa. The disks C may be assumed to revolve clockwise at a rate of thirty oer second. In the positions indicated in *ig. 2, the disk I) may be assumed to be at the counter clockwise limit of. its twenty degree excursion of revolution about B. \Vith the switch handle of F to the right under these conditions, the tube '1 is connected throughout the total time to condenser K through the two aforesaid rotary switches.- The coulombs per second will be a maximum under this condition. As the disk D is gradually rotated clockwise, the tube becomes intermittently connected to the'wndenser two hundred and seventy times per second. The percentage of total time connected gradually changes from one hundred per centto fifty r cent at the L clockwim limit of rotation o D. The switch F may then be thrown to the left and counter clockwise rotation of D will cause this percentage to vary from fifty per cent to zero per cent at the limit of counter clockwise rotation of D. This allows complete control of the number of coulombs per sec- Disk D is 0nd passing through. the tube While the ter- T neon-d in series. whereby Hm sparking at minai voltage is kept: at a fixed value during said points is minimized. all the, time the tube is producing rays. 1 In testimony whereof, I have hereunto I claim: 1 subscribed my name this 17th day of Sep- 5 A system for the pmduction of B'cinfgen tember, 1912.

ways comprising av sou'rseof high otential unidirecbimuzl ele cc x-ica]. cmmno a Gntgen ray tube :md means forconnecting and disconnecting said tube to and from said source 16 simultaneously at a number of points 0011- SE\VALL CABOT.

Witnesses E 13. TOMLINSON,

3110. K. \VOOIHYOHCll-L 

